When I had to drastically cut my fat intake, I modified a mayonnaise cake recipe. It's actually pretty good. You can top off a piece with whip cream, caramel ice cream sauce or canned fruit pie filling. Any if these can be used as filling and/or topping if you are making a layered cake.
Preheat oven to 350. Grease and flour 2-8 inch round cake pans or 1-8inch square cake pan. Set aside.(I love to use baker's joy or any other similar product)
In a medium mixing bowl, sift together flour, cocoa, soda, salt and sugar. Set aside. In a large mixing bowl, combine mayo, vanilla and milk. Beat with an electric hand mixer on low speed until smooth. Slowly add flour mixture to mayo mixture just until incorporated.
Pour batter into pan(s). Bake for 30 minutes or until toothpick in the middle comes clean. Turn out onto wire rack and allow to cool before frosting.